The statements above, if true, most strongly support which one of the following?

(A) The diet of A. robustus included at least some meat.

YES, we know that :

The A. robustus bones contained a lower ratio of strontium to calcium than did the erectus bones this implies they ate more meat that did erectus --> and if erectus had meat in there diet then A. robustus must have some meat in their diet too.

(B) The meat in the diet of H. erectus was higher in strontium than was the meat in the diets of other hominids.
No , we do not know abut all other hominids

(C) The diet of H. erectus was richer in calcium than was the diet of A. robustus.
No, we just know if it was rich in meat, nothing about calcium in the diet is given.

(D) The diets of A. robustus and H. erectus both contained less strontium than calcium.
No, The bones had this kind of ratio but not the diet, this cant be inferred.

(E) The process of fossilization altered the ratio of strontium to calcium in the bones of both A. robustus and H. erectus.
No, nowhere the question talks about it.

Answer: A